﻿// XMLFilter.java - filter SAX2 events.
// http://www.saxproject.org
// Written by David Megginson
// NO WARRANTY!  This class is in the Public Domain.
// $Id$
using System;

namespace org.xml.sax
{

    /**
     * Interface for an XML filter.
     *
     * <blockquote>
     * <em>This module, both source code and documentation, is in the
     * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
     * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
     * for further information.
     * </blockquote>
     *
     * <p>An XML filter is like an XML reader, except that it obtains its
     * events from another XML reader rather than a primary source like
     * an XML document or database.  Filters can modify a stream of
     * events as they pass on to the final application.</p>
     *
     * <p>The XMLFilterImpl helper class provides a convenient base
     * for creating SAX2 filters, by passing on all {@link org.xml.sax.EntityResolver
     * EntityResolver}, {@link org.xml.sax.DTDHandler DTDHandler},
     * {@link org.xml.sax.ContentHandler ContentHandler} and {@link org.xml.sax.ErrorHandler
     * ErrorHandler} events automatically.</p>
     *
     * @since SAX 2.0
     * @author David Megginson
     * @version 2.0.1 (sax2r2)
     * @see org.xml.sax.helpers.XMLFilterImpl
     */
    public interface XMLFilter : XMLReader
    {

        /**
         * Set the parent reader.
         *
         * <p>This method allows the application to link the filter to
         * a parent reader (which may be another filter).  The argument
         * may not be null.</p>
         *
         * @param parent The parent reader.
         */
        void setParent(XMLReader parent);


        /**
         * Get the parent reader.
         *
         * <p>This method allows the application to query the parent
         * reader (which may be another filter).  It is generally a
         * bad idea to perform any operations on the parent reader
         * directly: they should all pass through this filter.</p>
         *
         * @return The parent filter, or null if none has been set.
         */
        XMLReader getParent();

    }

    // end of XMLFilter.java
}